Myosotidium is a genus of plants belonging to the family Boraginaceae. This genus is represented by the single species Myosotidium hortensia, the Chatham Islands forget-me-not, which is endemic to the Chatham Islands, New Zealand.

Myosotidium hortensia is a fleshy herb reaching 60 cm or more high with huge glossy orbicular somewhat fleshy leaves and bearing clusters pale to dark blue flowers (1.7 cm in diameter) in the late spring. It can be dormant in winter in colder districts. It is much planted as a garden ornamental flower in New Zealand. There is also white form in cultivation.